Noise Floor Study

The RF noise floor is of interest to probably all radio amateurs, as many of us operate at low signal-to-noise ratios.  Many amateurs will be aware of rising RF noise levels in recent years from nearby sources of noise.

The RSGB has been concerned about protection of the RF noise floor for some time and was successful in elevating its concern to IARU with the acceptance of the following recommendation at the Region 1 General Conference in 2008:

Recommendation CT08_C4_Rec_05:

That the Conference agrees:

More effort should to be made to find and support volunteers who can address the general trend of liberalisation in spectrum management through:

1.Technically competent input and advice on HF radio propagation to professional groups who are sometime only versed in short-range EMC matters;

2.Setting up of a scientifically valid long-term assessment of the noise floor on Amateur Bands below 30MHz with the intent to raise complaint over general loss of spectrum effectiveness for the Amateur service,

and

that the HF Committee suggest to the other spectrum committees that a similar proposal and recommendation be considered for their spectrum areas.

The Noise Floor Study seeks to address directly the second point above, with hopefully some improvement on the first.

The Noise Floor Study is focused on studying the effects of Power Line Adaptors (PLA) and RF emanations from switched-mode power supplies, solar PV installations, Plasma TV’s etc, on the RF noise floor.  This will be in two parts.  Firstly, a look at the long-range impact and secondly support for the work by the EMC Committee on its study of the effects from nearby RF noise producing installations.

Both these aims will link with the “Noise Measuring Campaign” launched in 2012.  This invites UK amateurs to become involved, raising awareness of RF noise, its measurement, geographical distribution, daily and longer-term variation, etc.  It may though prove difficult to separate out the local from the long-distance impact, which is something the study will aim to resolve.

Studying the remote effects of RF noise from large conurbations is a particular goal of the Noise Floor Study.  As in all research the outcome is uncertain.  It may be that the established RF Noise Floor figures are unaffected; conversely the study may find a relationship with these relatively new sources of RF noise.  If the former, the experimental work can act as a baseline for a repeat of the work in say 5 years time.  If the latter, the RSGB will have some sound measurements for use in technical studies, etc, within CEPT and the ITU.  Having some independently and scientifically validated measurements would enhance our position in discussions within these bodies.

The Noise Floor Study is to be scientifically led by Prof. Mike Warrington, University of Leicester, and conducted through a series of MSc projects, supported by funding of approximately £10k through the generosity of the Ken Rowell, G5RL, legacy.  The funding mostly provides for equipment and the running cost of the data collection.  The study will be directed and project managed by volunteers within the RSGB with links to the Propagation Studies Committee and the EMC Committee.  The study is to start in late 2013 and is likely to take two or three years.  It will look for support from the amateur community during the experimental stages of the work.